Lubricating structure for leaf springs



'Aug. 26, 1952 J. L. SEARLE LUBRICAZIING STRUCTURE FOR LEAF SPRINGS 2 SHEETS-SHEET 1 Filed Nov. 7, 1949 INVENTOR. JOHN L. SEARLE ATTO R N EYS 26, 1 J. L. SEARLE 2,608,402

LUBRICATING STRUCTURE FOR LEAF SPRINGS Filed NOV. 7, 1949 2 SHEETS-SHEET 2 FIG.9.

INVENTOR. JOHN L.SE ARLE ATTORNEYS Patented Aug. 26, 1952 7 2,608,402 LUBRICATING STRUCTURE FOR LEAF SPRalN GS John L. S'earle, Detroit, Mich; assignor to Detroit Steel Products Company, Detroit, Mich., a corporation of Michigan Application November 7, 1949;"SerialNo. 125,910

The present invention relates to lubricating structure for leaf springs and more particularly, leaf 7 springs of the type used in automotive vehicles.

It is an object of the present invention to provide a positive simple lubricating structure for introducing lubricant between the contacting sur- 10 Claims. (Cl. 267-50) 2 Figure 7 is a view similar to Figure showing another modified grease fitting and assembly means therefor. Figure 8 is a view similar to Figure 5 showing still another modified grease fittingan-d'assembly means therefor.

Figure 9 is a plan view of a modified form of faces of leaf springs, particularly the areas grease fitting. thereof adjacent the ends of the leaf springs. Figure 10 is a section on the line Ill-40, It is a further object ofthe present invention 10 Figure 9. to provide grease fittings for applying lubricant Figure 11 is a bottom plan view of another under pressure to leaf springs. modified form of grease fitting.

It is a further object of the present invention Figure 12 is a section on th line l2l 2, Figure to provide a leaf spring construction including 11. j 7 means providing a reservoir intermediate adja- Figure 13 is a plan View of yet another modified cent leaf springs and adjacent the end thereof. form of grease fitting.

It is a further object of the present invention to Figure 14 is a section on the line I4|4, Figure provide a grease fitting in combination with 13. means for securing the grease fitting to a leaf Figure 15 is a bottom plan view of yet another" spring in a manner to form a grease receiving modified form of grease fitting. reservoir between such leaf spring and the next Figure 16 is a section on the line l6-l6, Figure, adjacent leaf spring of an assembly. v 15. Y

It is a further object of the present invention Referring now to the drawings, a spring asto provide leaf springs in combination with grease sembly of the type referred to is illustrated in fittings secured in openings in the leaf springs in Figure 1 and is composed of a plurality of leaves 7 which the grease fittings are permanently secured running from a short central leaf l0 through the to the leaf springs. progressively longer leaves ll, [2, l3, etc., to the It is a further object of the present invention upper leaf M which is longest of the set and which to provide grease fittings secured to openings is provided at each end with eyes [5 for attachformed in leaf springs in which the grease fittings ment to the shackles of the vehicle frame. The arev inserted through the openings and arev reassembly of leaves is provided with a center bolt tained in place by the next adjacent leaf spring [6' which holds the leaves together before inafterthe leaf springs havebeen assembled. stallation and serves as a locating dowel after It is a further object of the present invention installation. Clips H are used adjacent the ends to provide a grease fitting applied to an opening of some'of the'leaves to hold them in alignment in a leaf spring which is removable and replaceand prevent them from spreading. able after the leaf spring has been assembled with When the spring assembly is installed on a others. vehicle it assumes anapproximate straight con- Other objects and features of the inventionwill dition under load as illustrated in the figure. In become apparent as the description proceeds, es- 40 the operation of the vehicle the spring fiexesup pecially when taken in conjunction with" the acand down with a resultant relative movement companying drawings, wherein: between adjacent leaves longitudinally thereof. Figure 1 is a front elevation of a leaf spring This relative motionis at a minimum or is zero at assembly. the center bolt and is a maximum for each leaf Figure 2 is an. enlarged fragmentary section adjacent its ends. Accordingly, the maximum on the line 22,Figure 1. frictional resistance of the contacting rubbing Figure 3 is a fragmentary front elevation showsurfaces occurs at the areas adjacent the leaf ing one end of a leaf spring assembly. ends, causing wear and in some cases objection- Figure 4 is an enlarged fragmentary section able squeaking noises. on the line 4-4, Figure 3. It has long been recognized that lubrication Figure 5 is a fragmentary section through a between rubbing surfaces adjacent the ends of grease fitting applied to a leaf spring. leaf springs is desirable. It has been suggested Figure 6 is a view similar to Figure 5 illustratin the past to provide grease fittings for introing amodified grease fitting and assembly means ducing grease into the spring assembly and to therefor. provide interconnecting holes adjacent leaf secannular. flange Z'I sj eat-ed against th 'e'outer sur ace,

tions'to allow the lubricant to circulate to the trated a leaf spring assembly provided with a several contacting surfaces. This method has plurality of fittings 35 which may be of the type proved impractical however, ce under v c illustrated in Figure 2. In addition, the assembly conditions satisfactory lubrication of all of the 7 includes a plurality of clips 36. In this case the surfaces is not obtained. It has also been suggrease fitting'38 extends through the clips 36 sted o p o e l i pregnated liners or inand through the next adjacent leaf spring illusserts between spring sections and toprovide metal trated here Ml. The ;:fitting1-38 isproyided with prin advers- Ma y of "th previ ly suggested an outwardly extending flange 42 roamin -a shouldevices for Obtaining this result are not p d-er adapted to seat on the outer surface of the able because they add excessively to the cost of; ;.Qlip 36. The leaf spring 40 has an opening therethe spring asembly. Others are not acceptable through including a cylindrical portion 44 and a because they fail to provide positive lubri'catiorr iconicalp'ortiondt. The fitting 38 adjacent its at the critical areas. inner end has a thin walled reservoir 41 formed According to the present invention a separate'; I thereinthe walls ofthereservoir being swaged or grease fitting is provided adjac nt he nd i otherwise; formed outwardly to interlock the fiteach leaf spring where lubrication is essential. ting-with'the clip 36 and the leaf spring 46. The While in theory it is desirabletovprovidea single. adjacentsurfacesof. the leaf spring 43 and the fitting for introducing lubriainttfl plurality nez't lower springare bowed transversely to leave leaf p in e e practical experience has. 7 space therebetwe-en through which grease flows indicated that this resultcannot be obtained. Aclongitudinally of the spring assembly.

cordingly, a. separate grease fitting is appliedto Ref erring now to Figure 5 there is illustrated a the. end ofeach leaf spring which it is desired .mo'difiedformof iitting. ,ln this caselthe leaf to lubricate. Moreover, by providinggrease fitspringv 50 has an opening 52- provided therein.

tingsofthe. pressure type .the possibility that luwhich may if desired be'threaded'. Adjacent the brication willbeoverlooked duringpe'riodiclubri inner side of the leaf spring 53 the opening 52 cation of the vehicle is minimized. The several fiaresoutwardly to provide conically shaped walls,

fittingsillustrated in the. drawings have thecom- 54.. The fitting 58 is providedwith threads on mon feature that each allows direct lubrication of its exterior and may be retained in place b ya the areas, at the ends of theleaves ata minimum lock nut 58. LThe. inner 'endof the fittingIliasv of cost. The nipple of the fitting is madeior an outwardly .fiaredskirt portion 60' which serves use witha standard service station greaselglun. asaistopl Theformationlprovides.ajlaterallyen The specific structural: arrangement by which the. larged lubricant reservoirtL V 1 grease fittingsjareappliedfto the. leaves. of, the Referring now to Figure" 6. there. is illustrated a spring results in the formation of a reservoir in lubricant f tting which is adapted to'be ;.re movwhich a substantial quantity. oflubricant is, reable andlreplaceablewithout disturbing the as; tained and from which reservoir such lubricant ser'nbly of leafsprings; ,Inthis caseav leaf. spring may move during use, in orde'rfto keep 'thela'f (i5; is. provided. withv anlopening t'filitherethroughr spring assembly lubricated in the most efficient which is outwardlytapered at the} innerjside I manner. shown to provide a laterally enlarged lubricant.

' In general, the fittingsillustratedlinthe.draw- 4o r se v irgssz. The lubricantfitting Hi bass stern ings, may be subdividedinto three classes which portion 'l'z whichis serratedwith teeth aei11us.

will be discussed separately. In the'firs't place trated. In o'rderto retaintheffitting I9 in'th'e the fittings illustrated. in Figures 2-5, are peropening 56 a grommet 4px. a'qsuita'bl'e. resilient manently'secured to a; single leafjspring." In the material is provided. Conveniently, the. gromr. mbodiments of the invention illustrated .in Fig- 45. m may be formed of'neopr e 1 Other" i ures 6 1 0 thefittings are detachable from .',the' sist'a'nt synthetic, rubber. 'Theflteeth on the ste leaf spring inwhichthey are mountedfwhilejthe I 12are s'uch that' the fitting "'Hl may beintr'odu d leaf spring remains in assembly. The modificainto. the resilient grommet 14 by the application tions of theinvention illustrated in Figureslzglfi ffi'pf sure and. is retain r in by. n a e-i arereceived injopeni s in 'singleleaf spring'fla'hd, mentjbetween' the teeth of the stern ,andf the are retained therei y engagement withfthe ro met However; despiteth'e greater. res t.'- next adjacent leaf of" the ass'e'mblyg" In thisgtype ance offered to withdrawal oi the fitting rede ne; therefore in order 'to"rem'ov-e .and rep1a Ce a l;tT- grommet); it n'i'ay if desiredj be removed. or'if' ting it necessarytodisasseinblethe spring, SF? damaged and'lost'it may be readily replaced? sembly or at least to'move'theportion of'the "The; modification illustrated in Figure??? is. leaf which supports the fitting away fromthe simil'artofthat shownin'Figure. 6- and differs t jacent leaf spring. ,1 I primarily in the manner in'whichjthel openinglfl. [R i g n w tq ure 2 th f t n .2 .reis provided'in the leaf spring 80. Inthis casethe ra d wit nen Ope n forme i -al a Sh i e metal surrounding the opening 78 and. theleaf 221 thej nenine havingacylindrical portion 24. G0 fn' f n ali r n 25+ Th fittmg Q has an reservo r fl of substantially increased size. ,5

ofj -the v leaf 22 4 and a laterally enlarged: reservoir 28bounded at its shoulders by relatively thin walls a Whm a swaged mm formed 4 engage Figure Bthe eisi1lustrateda thegad' acent wallsurfaces 24 and 26jinfthe leaf Sprmg'. There is thus provided a lubricant-reset: modified arrangement inwhlch the leaf springv voirfili' of. substantial size, the sides, of this reser isi-providegf W it? 9 m gihaving i voir being formed in part by the..fi'tting mtapered sldes adjacent rlts' su a part; by the Opening through th f i 'n to provide a lubricant receiving reservoir 9%. The and the, end; of 'thereseryoir being-closed c ja nt surface of the next-adjacentleafgspring. h nsm fi i tfi ss 1 .11 10W.

.shaped outwardly so as to prdvide a In this case the fitting: 8 l=;i;s;secured in azgrommet; Win-substantially thesa-Ine manner as the hisgrease f tting Sit carries acollarfia .havingaplu The. fitting 2B is thus permanently attached to portions ohthes'egfih rsbein bent outwardly to el a Pr sH-"i ii;-

y I e a t fi erjini la b isne e w h liteferring nowto Eiguresifi' and l thereis i'llu's- (5. thetapered walls of the opening'92. A suitable washer is illustrated at I02 and serves to seal the reservoir 94. I 1 I. 7

Referring now to Figures 9 and'lO there is illustrated an arrangement in which the spring III] is provided with a conically tapered opening I I2 for the reception of a corresponding tapered plug II 4. The plug' I I4 is provided with an internally threaded bore II6for the reception of the grease fitting H8. The plug II4 has a flat sided neck I and the fitting II8 may be of hexagonal shape as indicated at I22 so that the fitting may be removed from the plug I I 4. In order to facilitate radially outward fiow of grease under pressure or under conditions encountered in use, the lower surface of the plug H4 is provided with a plurality of radially extending channels I24. 'In use, the plug H4 is retained in position by engagement with an underlying leaf spring which also serves to close the oil reservoir I25 provided therebetween. The channels I24 as previously described, permit outwardfiow of lubricant from the reservoir I26. The plug I I4 and the hole into which it fits may be of circular cross-section,-;or ofnon-circular cross-section, such as square to prevent rotation of the plug in the hole. The plug I I4 extends below the lower surface of the spring III] to engage the upper surfaceof the next adjacent leaf spring, a portion of which is illustrated at I28. Lubricant fiows out of channels I24 into the space I29 between the springs.

Referring now to Figures 11 and 12 there is illustrated an arrangement in which the leaf spring I3!) is provided with a conically tapered opening I32 therethrough. In this case the grease fitting comprises a single element I34, the lower portion of which is conically formed to fit within the conical opening in the leaf spring I30. Again, radially extending channels I36 are provided at the underside of the fitting I34 to permit outward flow of lubricantfrom the central lubricant reservoir I38.

Referring now to Figures 13 and 14 there is illustrated an arrangement in which a leaf spring I4I.'I.is provided with an opening therethrough comprising a smaller upper portion MI and an enlarged bottom portion I 42. The fitting I43 is received within the opening and comprises a neck portion I44 extending through the smaller opening I42 and a bottom portion I45 received within the enlarged portion I42 of the opening. Intermediate the top of the enlarged portion I45 of the fitting and an overlying shoulder portion I46 of the spring is a sealing gasket I 41. The underside of the fitting I43 includes a conically shaped reservoir portion I48 and in addition, the radially extending channels I49 are provided for the flow of lubricant out of the reservoir I48.

Referring now to Figures 15 and 16 there is illustrated an arrangement in which the spring I has a downwardly and outwardly tapered conical opening I6I. Suitably received within this opening is a plug I62 which may be formed of a suitable compressible material such for example as an oil resistant synthetic rubber. The fitting I63 has an outwardly extending flange I54 embedded in the plug I62. The inner portion of the plug I62 is laterally enlarged to provide a lubricant receiving reservoir I65 and its lower surface is provided with a plurality of radially extending passages I66 for outward flow of lubricant from the reservoir. Again, this fitting is inserted from the inner side of the leaf spring I60 prior to assembly and is retained in position therein by the next adjacent leaf spring engaging the under-surface of the plug I62.

In general, the opening in'the leaf springinwhich the fittings are'secured may be punched therein and in some cases they may be countersunk as shown. In cases where the thickness of the leaf spring isinsufiicient to permit countersinking, the material of the spring surrounding the opening may be formed'upwardly. I

It may be mentioned at this time that leaf springs for vehicles of the type described herein are normally provided with a slight transverse camber or dish which further facilitates lubrication in that it tends to direct lubricant applied under pressure between the springs longitudinally thereof.

Fittings may be made of any suitable material, but excellent results are obtained when aluminum silicon bronze is employed. r

Springs supplied with fittings of the type disclosed herein will be lubricated as a'matter of course whenever the vehicle is given a general lubrication. The fittings are extremely economical and do not add appreciably to the cost of the spring assembly although they improve its utility and result in longer life than would otherwise be the case.

While reference is made to upwardly extending fittings to simplify the description it will be understood that in reversed spring assemblies of the type shown in Figurel, the various elements are merely inverted. So also in full; elliptical springs, fittings on one part will be inverted with respect to fittings on the other part.

The drawings and the foregoing specification constitute a description of the improved lubricating structure for leaf springs in such full, clear, concise and exact termsas to enable any person skilled in the art to practice the inventiomthe scope of which is indicated by the appended claims.' e

What I claim as my invention is:

1. Spring construction for motor vehicles comprising an assembly of leaf springs of progressively stepped lengths, means for applying lubri cation under pressure to the surfaces adjacent the end of a shorter leaf and the contiguous surface of the next longer leaf, said shorter leaf having a transverse opening therethrough adjacent its end, said opening being fiared at its end next to the longer leaf, said means comprising a pressure grease fitting in said opening, said means having a portion extending above said shorter leaf and a portion within said opening extending laterally to bear against the flared surface surrounding said opening, the portion of said fitting above said shorter leaf being dimensioned to pass through said opening to provide for removal of said fitting upon disassembly of said shorter and longer leaf.

2. Spring construction for motor vehicles comprising an assembly of leaf springs of progressively stepped lengths, means for applying lubrication under pressure to the surfaces adjacent the end of a shorter leaf and the contiguous surface of the next longer leaf, said shorter leaf having a transverse opening therethrough adjacent its end, said opening being flared at its end next to the longer leaf, said means comprising a pressure grease fitting in said opening, and an adaptor separate from said fitting, said adaptor including means releasably securing said adaptor in said opening.

3. Structure as defined in claim 2, said adaptor being formed of resilient material including laterally extending portions above and below said opening to retain said adaptor in said opening,

and; beinedistortable to; provide. for removal of saidadaptor incur-said opening; I Y 41;. Structure as defined in claim 3,sai;d fitting including a. portion; releasably secured in said adaptor'to provide..f0r removal of saidi fitting from-said adaptor. V x

5. Structure as definedin claim 3",. said; adaptor having an opening. theret-hroug-h; and saidfitting having a serrated; stem removably: secured; in; the opening;-' in said adaptor. i .6; :Structure: as defined in claim 3;. said: adaptor beingliormedof rubber. I

- 1 7 Spring construction for motor vehicles comprising an assembly of leaf springszoi p-rogres-M sivelyr stepped lengths, means; for applying: lubrication: under pressure. to the; surfacesiadj acent the end of a shorter leafand the contiguous sur face of the next longer leaf, saidshorter leaf having a transverseopening therethrougho ad.-

jacent its end, saidopening, being flared at its :4

endvnext to the longer-leaithewall portion surrounding said opening being of reduced, thickness-and formed outwardly of' the plane of said leaf: to provide an enlarged lubricanttreservoin said means comprising a resilient generally tubularadaptor' received: in saidopening having laterally extending; portions atxboth. endsziof said opening to retain said, adaptonin said-openings, pressure. grease fitting-having; a, serrated stem in said. adapt r, saidadaptor and fittingbeing re r movable bydistortion of them-aterial of said adaptor fromsaidopening, saidfitting being removable andreplaceable: from said adaptor;-

1 8. Structureas defined inclaimflin which the innerendofsaid fitting and adaptor are-spaced substantially from the -,adjaeent surface of-sa-id oq'n l flq ..9i..' Spring construction'for'motor vehicles comprising an assembly of leaf springs of progressively stepped lengths, meansfor applying-lubrication under pressureto the surfaces adjacent the. end ofa shorter leaf and thecontiguous surtace. of the. next longer leaf, .said shorter leaf having a transverse opening therethrough adjacent; itsen'd said. opening being flaredat its end 8. next to theslonger. leafiisaid means comprising-1a pressure grease fitting in said opening havingia portion extending: above said shorter leaf dimensionedjto pass through said opening and Elatierally enlargedportion-beyond the top ofsaid' openingengageame with the; :SIlIfaCEWOi'T said shorter leaf adjacent saidlonge'r. leaf: to prevent outward removal of said: fitting, whereby" said having a transverse; opening therethrouglr 'adj ai- 7 cent its end, said opening beingjflared attitsend next to the: longer leaf, said means comprisinga pressure grease fitting in said: opening" havin'gr-ap-ortionextending above saidshorterleafand an adaptor in which said fitting is s.eoure:d;v said adaptor having alaterally extending portiomen gageable with the flared-surface: of isaid to p ning to retain said adaptor and fitting iIL 'POSitiOH A JOHN L. SEARLE.-"

L ap earancesoman v The following" referenees are-ref 'recordfi'nth'e file of this" patent: fl

' STATES PKTENTS 

